feat: clock + place games

polylan_submitter/clock/scoring.py

@@ -0,0 +1,37 @@
+from django.db.models import ExpressionWrapper, F, FloatField, Q, Sum, Value, Window
+from django.db.models.functions import Coalesce, Power, Rank
+
+from events.models import Event
+
+# points = 1000 * (1 / (remaining_seconds + 0.5)) ** 2, computed per press and
+# summed per player. Never stored - always derived live from Press rows.
+POINTS_BASE = 1000.0
+POINTS_OFFSET = 0.5
+POINTS_EXPONENT = -2.0
+
+
+def _press_points_expression():
+    base = ExpressionWrapper(
+        F("clock_presses__remaining_before_press") + Value(POINTS_OFFSET),
+        output_field=FloatField(),
+    )
+    return ExpressionWrapper(
+        Value(POINTS_BASE) * Power(base, Value(POINTS_EXPONENT)),
+        output_field=FloatField(),
+    )
+
+
+def ranked_players(event: Event):
+    """All users annotated with their live total points for this event and
+    DB-computed RANK(). Points only ever come from presses made in `event` -
+    a player's history in another event never leaks into this leaderboard."""
+    from accounts.models import CustomUser
+
+    points = Coalesce(
+        Sum(_press_points_expression(), filter=Q(clock_presses__event=event)),
+        Value(0.0),
+        output_field=FloatField(),
+    )
+    return CustomUser.objects.annotate(points=points).annotate(
+        rank=Window(expression=Rank(), order_by=F("points").desc())
+    )